Model-Based Motion Planning for Robotic Assembly of Non-Cylindrical Parts

In high-speed part mating using robotic arms, the dynamic characteristics of the mating process have to be considered. This paper first derives the geometrical compatibility condition for the insertion motion where mating force/moment are free of overshooting. Simulation studies are then carried out where the dynamic characteristics of a robot, subjected to contact force and moment, are formulated and solved numerically. On that basis, the worst case among different types and combinations of misalignments is predicted and a varying speed insertion motion is synthesised. Experimental investigations involving square peg mating using a SCARA robot are presented. The experimental results show that with such a varying-speed motion, assembly operations can be carried out in a reduced cycle time without inducing excessive contact force and moments.